whisper: error handling changed

cmd/wnode/main.go

@@ -309,7 +309,10 @@ func configureNode() {
 		Topics:    []whisper.TopicType{topic},
 		AcceptP2P: p2pAccept,
 	}
-	filterID = shh.Watch(&filter)
+	filterID, err = shh.Watch(&filter)
+	if err != nil {
+		utils.Fatalf("Failed to install filter: %s", err)
+	}
 	fmt.Printf("Filter is configured for the topic: %x \n", topic)
 }
 

whisper/whisperv5/api.go

@@ -215,8 +215,7 @@ func (api *PublicWhisperAPI) NewFilter(args WhisperFilterArgs) (string, error) {
 		}
 	}
 
-	id := api.whisper.Watch(&filter)
-	return id, nil
+	return api.whisper.Watch(&filter)
 }
 
 // UninstallFilter disables and removes an existing filter.

whisper/whisperv5/filter.go

@@ -53,8 +53,7 @@ func NewFilters(w *Whisper) *Filters {
 	}
 }
 
-func (fs *Filters) generateRandomID() (id string) {
-	var err error
+func (fs *Filters) generateRandomID() (id string, err error) {
 	buf := make([]byte, 20)
 	for i := 0; i < 3; i++ {
 		_, err = crand.Read(buf)
@@ -70,16 +69,13 @@ func (fs *Filters) generateRandomID() (id string) {
 			err = fmt.Errorf("error in generateRandomID: generated same ID twice")
 			continue
 		}
-		return id
+		return id, err
 	}
 
-	// at this point all the attempts to generate the random ID failed.
-	// this poses a serious danger, since whisper very much relies
-	// on random numbers. the program must be terminated.
-	panic(err)
+	return "", err
 }
 
-func (fs *Filters) Install(watcher *Filter) string {
+func (fs *Filters) Install(watcher *Filter) (string, error) {
 	if watcher.Messages == nil {
 		watcher.Messages = make(map[common.Hash]*ReceivedMessage)
 	}
@@ -87,9 +83,11 @@ func (fs *Filters) Install(watcher *Filter) string {
 	fs.mutex.Lock()
 	defer fs.mutex.Unlock()
 
-	id := fs.generateRandomID()
+	id, err := fs.generateRandomID()
+	if err == nil {
 		fs.watchers[id] = watcher
-	return id
+	}
+	return id, err
 }
 
 func (fs *Filters) Uninstall(id string) {

whisper/whisperv5/filter_test.go

@@ -100,9 +100,13 @@ func TestInstallFilters(t *testing.T) {
 	filters := NewFilters(w)
 	tst := generateTestCases(t, SizeTestFilters)
 
+	var err error
 	var j string
 	for i := 0; i < SizeTestFilters; i++ {
-		j = filters.Install(tst[i].f)
+		j, err = filters.Install(tst[i].f)
+		if err != nil {
+			t.Fatalf("seed %d: failed to install filter: %s", seed, err)
+		}
 		tst[i].id = j
 		if len(j) != 40 {
 			t.Fatalf("seed %d: wrong filter id size [%d]", seed, len(j))
@@ -519,13 +523,17 @@ func TestWatchers(t *testing.T) {
 	var j uint32
 	var e *Envelope
 	var x, firstID string
+	var err error
 
 	w := New()
 	filters := NewFilters(w)
 	tst := generateTestCases(t, NumFilters)
 	for i = 0; i < NumFilters; i++ {
 		tst[i].f.Src = nil
-		x = filters.Install(tst[i].f)
+		x, err = filters.Install(tst[i].f)
+		if err != nil {
+			t.Fatalf("failed to install filter with seed %d: %s.", seed, err)
+		}
 		tst[i].id = x
 		if len(firstID) == 0 {
 			firstID = x

whisper/whisperv5/peer_test.go

@@ -122,7 +122,10 @@ func initialize(t *testing.T) {
 		topics := make([]TopicType, 0)
 		topics = append(topics, sharedTopic)
 		f := Filter{KeySym: sharedKey, Topics: topics}
-		node.filerId = node.shh.Watch(&f)
+		node.filerId, err = node.shh.Watch(&f)
+		if err != nil {
+			t.Fatalf("failed to install the filter: %s.", err)
+		}
 		node.id, err = crypto.HexToECDSA(keys[i])
 		if err != nil {
 			t.Fatalf("failed convert the key: %s.", keys[i])

whisper/whisperv5/whisper.go

@@ -272,7 +272,7 @@ func (w *Whisper) GetSymKey(name string) []byte {
 
 // Watch installs a new message handler to run in case a matching packet arrives
 // from the whisper network.
-func (w *Whisper) Watch(f *Filter) string {
+func (w *Whisper) Watch(f *Filter) (string, error) {
 	return w.filters.Install(f)
 }